1. Field of the Invention
The present invention relates to an operating head for removing and fitting wheel tires for vehicles.
2. The Prior Art
It is known that vehicle wheels generally comprise a metal rim having along the perimeter thereof annular flanges amid which are fitted fast up the end portions, so-called “beads”, of an elastic tire.
The use is currently known of so-called “tire-changing” machines, suitable for removing and fitting the tire from the relevant rim for carrying out, e.g., maintenance, repair or replacement jobs.
In particular, different types of tire-changing machines of automatic type are known comprising an operating head having a retracting tool for removing the tire and which is associated with a mobile arm of the machine movable in terms of height and horizontally by means of relevant actuators.
The removal tool has a curved end part suitable for gripping the tire bead.
In particular, the removal tool is mobile, by means of a machine actuator commonly mounted on the mobile arm, between a bead gripping position, in which it extends from the operating head and positions between the annular flange of the rim and a section of the tire to be removed, and a position of extraction of the edge of the tire, in which it is raised to extract the section of the bead gripped above the annular flange of the rim.
During use, an operator positions and blocks the wheel on the coupling and rotation means and, by means of a special beading tool, performs a first preliminary detachment phase of the tire bead from the annular flanges of the rim.
Subsequently, the operator regulates the position of the operating head with respect to the frame according to the specific dimensions of the wheel.
The tool is then conveyed to the coupling position and the end part of the tool presses on the side of the tire until it is introduced between the tire bead and the relevant flange on the rim, until the hooked extremity of the tool is positioned so as to withhold the tire bead.
Subsequently, the tool is positioned in the extraction position so as to extract a portion of the bead above the rim.
The rotation of the rim then enables the entire bead to come out of the respective flange.
These known machines do however have a number of drawbacks.
The movement of the tool in fact is performed by means of one or more tire-changing machine actuators, generally integrated on the mobile arm of the machine itself.
This necessarily means using operating heads that have specific structural characteristics for each tire-changing machine and which are therefore hard to adapt for use on different tire-changing machines.
Furthermore, during the removal operations performed with the operating heads commonly used, unwanted deformations of the tire bead can occur, due mainly to the excess tension exercised by the tool during the extraction movement of the bead above the annular flange of the rim.
The main aim of the present invention is to provide an operating head for removing and fitting wheel tires for vehicles that can be installed in a simple and quick way on different types of tire-changing machines.
Another object of the present invention is to provide an operating head for removing and fitting wheel tires for vehicles that allows reducing the tensions exercised by the tool on the tire bead during the extraction movement above the annular flange of the rim.
Another object of the present invention is to provide an operating head for removing and fitting wheel tires for vehicles that allows to overcome the mentioned drawbacks of the background art in the ambit of a simple, rational, easy, effective to use and low cost solution.